Firearm shooting sports are often associated with the sometimes painful recoil that may result from shooting firearms. Recoil from large caliber firearms can cause a shooter to flinch or jerk the firearm trigger in anticipation of the shock to the shooter's upper body. Flinching or jerking the trigger in anticipation of recoil is a common negative factor in a shooter's accuracy. Recoil can be described as the equal and opposite reaction to the momentum of an ammunition cartridge's projectile (e.g., bullet) and gunpowder charge upon firing of the cartridge. This momentum is imparted to the firearm, causing it to travel in the opposite direction of the fired bullet. The resulting recoil energy of the firearm can be calculated using the following equation derived from the Law of Conservation of Momentum:
      Recoil    ⁢                  ⁢    Energy    ⁢                  ⁢          (              ft        ⁢                  -                ⁢        lbs            )        =                    (                              Bullet            ⁢                                                  ⁢            Weight            ×            Bullet            ⁢                                                  ⁢            Velocity                    +                                          ⁢                                          ⁢                      4700            ×            Gunpowder            ⁢                                                  ⁢            Weight                          )            ⁢                                   ⋀                ⁢        2                    64.348      ×      Firearm      ⁢                          ⁢      Weight      Where 4700 is the velocity of the gases generated by the burning gunpowder and 64.348 is a correction factor for the acceleration of gravity.
As can be seen by the above equation, increasing the Firearm Weight will result in a decreased Recoil Energy. As is common to the art of firearm manufacture, large caliber, heavy recoiling firearms are designed to be heavier in weight than small caliber, low recoiling firearms for precisely this reason. The additional weight has a dampening effect on the recoil felt by the shooter.
To test the accuracy of a firearm, a shooter will commonly shoot with the firearm placed atop a shooting rest, which in turn is placed on a bench. The shooter then fires the firearm from a sitting position behind the bench. This type of arrangement minimizes the shooting errors caused by the inability of the human body to hold a firearm perfectly steady and provides a steady, accurate method of supporting a firearm while shooting. Shooting from a bench has the drawback of subjecting the shooter to a higher degree of “effective recoil.” Actual recoil energy of the firearm does not increase by shooting from a bench, but more of the recoil energy is transferred to the shooter in a sitting position than in a standing position. The standing position allows the entirety of the shooter's body to flex and partially absorb the recoil energy. In the sitting position, however, only the torso (i.e., shoulder to waist) of the shooter is available to flex and absorb the recoil. Because of the higher “effective recoil” when firing from a sitting position, shooting a large caliber, heavy recoiling firearm from a bench can create an unpleasant experience when firing more than a few rounds. It is common for a shooter to fire upwards of twenty rounds when zeroing, or sighting-in, especially in the case of rifles and shotguns using telescopic sights.